The present invention relates to a packing material for high-performance liquid chromatography, and provides a packing material having an excellent separating capacity with little dispersion particularly in the field of separation of optical isomers.
There are a variety of packing materials for high-performance liquid chromatography, examples of which include one comprising a granulated (crushed or bead-like) substance having a separating capacity in itself, one having such a substance chemically bonded to a carrier, and one having a carrier coated with such a substance. Particularly in the field of separation or optical isomers, a packing material having a carrier coated with an optically active substance having the capacity of separation of optical isomers is actually used in many cases. Known examples of such a packing material include one having a carrier coated with an optically active crown ether compound as a low-molecular compound (JP-A 62-210053), one having a carrier coated with an optically active triphenylmethyl methacrylate polymer as a synthetic polymer (JP-A 57-150432), one having a carrier coated with cellulose triacetate as a derivative of a polysaccharide (JP-A 60-82858), one having a carrier coated with cellulose benzoate (JP-A 60-40952), and one having a carrier coated with cellulose phenylcarbamate (JP-A 60-108751), which are commercialized and widely used by virtue of their high optical resolving powers.
However, columns packed with such a packing material, even if packed with the same packing material, sometimes cause a large difference in separating performance, sometimes a good separation but sometimes a poor separation depending on different production lots of the packing material, when some racemic compounds as an object of separation are used. Particularly in the case of preparation (or aliquot), when separation is poor, it is unavoidable to resort to a low-efficiency separating operation by, for example, decreasing the flow rate of a mobile phase. into the column or decreasing the feed rate of a sample.
With a view to coping with the foregoing problems, an object to be solved by the present invention is to provide a packing material having a carrier coated with a substance having a separating capacity for high-performance chromatography, wherein the capacity of the packing material can be sufficiently exhibited with little dispersion of separating capacity thereof.